Functional Explanation, Science, and Religion
I am pressing ahead with Peter McLaughlin’s What Functions Explain. Although I have more reading to do– and McLaughlin is judicious in his pacing, frustratingly raising interesting questions and promising to engage them in later chapters so as to continue on a single subject– his discussion of the etiological approach to functional explanation raised some interesting thoughts having to do with a contrast between certain practices in science and religion.
Let me go over that territory again before linking functional explanation to science and religion. Exactly what entails a functional explanation– or an explanation of some entities function– is difficult philosophical territory. In contemporary philosophy, there are two main competing schools on what a function should consist of, originating with Thomas Nagel and C.G. Hempel. The etiological approach to functional explanation relies on including a causal aspect in the explanation. Instead of a nomological statement or two– along the lines of:
The function of an item X in a system S is to do Y, which under some condition C (including internal state Ci and environmental context Ce) is required for, or is at least conducive to, goal G. (McLaughlin, 2001, 68)
The Hempelian variation on this theme is broken into three parts by McLaughlin, namely disposition, welfare, and feedback. Disposition is the tendency of something– an organ, artifact, organism, or other entity– to do something under some condition (as above). The welfare condition is that that something tends to promote a goal of that entity. Finally, the feedback loop is the etiological (causal) characteristic of the explanation. It relates to how the entity has come to perform its function and how the performance of that function is vital to the continued existence and performance of that entity. In other words, it isn’t enough for a functional explanation to feature a means and an ends: it must also feature how the performing entity came to be a function bearer, and continues to exist as such. It must be part of the function of a thing to put it in place to perform its function in the first place, instead of its coming to perform its function by accident.
Naturally, this account raises all sorts of problems. I will take McLaughlin at his word, though, and continue on in his text before I take the plunge into that discussion. For now, I’m going to ignore some of the problems with the etiological account of functional explanation and go forward with how such explanation is illuminating for a description of science and religion. At least some of the time– when there aren’t issues with the vagueness surrounding the term “function”– I think scientific explanation makes use of this kind of explanation. In particular, the issues scientific explanation would have with function seem more oriented towards the dispositional and valuational characteristics of functions and not the etiological aspect. The opposite seems true of religion.
One of the issues, of course, is that of teleology and its attendant baggage of intentionality. The more interesting issue is that of the causal feedback loop. The issues scientists have with teleology and its gestures towards an unknown agency are fairly well-known, and so I will leave them to other authors or separate posts. What caught my interest today are the different demands of science and religion on functional explanation. Science seems to demand an etiological component, and religion does not. This is because of the two different approaches science and religion have towards causation. Religion, (if the definition includes some content regarding the supernatural) is not merely permissive of interrupted causation in the natural world– it is demanding of it. Science, on the other hand, stresses a uniformity of causation in the universe.
The significance of this is that causal feedback loops may be an essential ingredient of an adequate scientific explanation, while they create a source of tension with some religious explanation. A causal feedback loop provides closure in an explanation– the heart is frequently used as a classic illustration of this. The function of the heart is to pump blood, which certainly contributes to the welfare of the organism that contains the heart. As long as the heart continues to pump blood, the organism will continue to live and cause the heart to pump blood. Short of some interruption in the system, the heart will continue to function. The heart was developed particularly to do this, in that sort of system, and will continue to do so unless interrupted or replaced.
If one insists on a more intentional world (at the extremes, this consists of belief in special creation), this explanation might seem incomplete or unsatisfactory. “Why,” such a person might ask, “did the heart come into existence at all?” This question is intended not to probe the intricacies of the causal reinforcement loop– the reply, “it developed to pump blood” is really only a restatement of the information contained above, and it is not the sort of answer the questioner is after, anyway. This is because such a question is intended to step beyond the causal loop, and beyond the uniform sort of causation contained within. Doing so does away with the need for the etiological condition, reducing functional explanation to the dispositional and the valuational while providing an overlaying agency to the world. Now, the explanation for the function of the heart is this: The function of the heart is to pump blood, which certainly contributes to the welfare of the organism containing the heart. The heart came into being with organisms that required them to, themselves, function. It is not difficult to imagine this line of thought terminating in something akin to Aquinas’ arguments, a sort of regress that ends in the divine. This is a familiar sight in philosophy– if unsatisfied with a loop, the other choice is a regress. What had not occured to me before is how scientific explanation tends to be comfortable with the one, and religious explanation the other.